Your washer has a built in diagnostic on the inverter board on the motor. Take off the front cover by inserting a screw driver or putty knife in the gap between the front and top near the edges to release clips that hold the front on.

If you have blinking lights on the motor this site will show you how to interpret them. Try resetting the system using the instructions and see if that fixes things. If not, look at the codes, but the likely problem is the mode shifter which in my opinion because of the cost means a replacement machine is due.

HydroWave GE Washer Repair Guide